Technical Field
The present invention relates to thermal power generation technologies and saline water desalination technologies, in particular to an electricity-water co-generation system and method.
Description of Related Art
As shown in FIG. 1, in the current thermal power generation technology, fuel is burning in a boiler to heat water into overheat steam; the overheat steam drives a steam turbine to drive a generator to generate electricity; the overheat steam releases potential energy to do work, and changes into spent steam; the spent steam is delivered to a condenser to release heat energy and then generates condensed water; the condensed water is heated by a low voltage heater, deaerated by a deaerator, heated by a high voltage heater and then delivered to the boiler, and re-heated by the boiler into the overheatsteam for doing working, thus forming steam-water circulation to generate electricity continuously. In this process, about 40% of the chemical energy of the fuel can be converted into the electric energy; about 9% changes into production consumption; about 6% is the loss of the smoke exhausting heat of the boiler; about 45% is the cold-end heat loss generated by the heat energy through which the condenser discharges the spent steam to the environment. Those heat losses cause huge heat waste. Besides, in this process, it is needed to continuously supplement boiler supply water that is manufactured by chemical desalting to the deaerator, so the cost is high and equipment is complicated.
Existing saline water desalination technologies mainly include distillation methods, electrodialysis process and reverse osmosis process. Those methods are disadvantaged in large energy consumption and high cost. Besides, among the distillation methods, in order to prevent the equipment from scaling, high-temperature distillation method cannot be used, so only low-temperature distillation methods such as low-temperature multiple-effect method and multi-level flash method can be used, which has low water generation efficiency.
Therefore, the present invention provides an electricity-water co-generation system and method to solve problems existing in the thermal power generation and saline water desalination.